bug 537 - Node Reconciliation

[controller.git] / opendaylight / md-sal / forwardingrules-manager / src / main / java / org / opendaylight / controller / frm / FlowCookieProducer.java

diff --git a/opendaylight/md-sal/forwardingrules-manager/src/main/java/org/opendaylight/controller/frm/FlowCookieProducer.java b/opendaylight/md-sal/forwardingrules-manager/src/main/java/org/opendaylight/controller/frm/FlowCookieProducer.java
new file mode 100644 (file)
index 0000000..d7b54e8
--- /dev/null
+++ b/opendaylight/md-sal/forwardingrules-manager/src/main/java/org/opendaylight/controller/frm/FlowCookieProducer.java
@@ -0,0 +1,79 @@
+/**
+ * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+
+package org.opendaylight.controller.frm;
+
+import java.math.BigInteger;
+
+import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.Table;
+import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
+
+import com.google.common.base.Preconditions;
+import com.google.common.util.concurrent.AtomicLongMap;
+
+/**
+ * forwardingrules-manager
+ * org.opendaylight.controller.frm
+ *
+ * Singleton FlowCookieProducer contains a FlowCookie generator which is generated unique
+ * flowCookie identifier for every flow in same Table. That could help with quick
+ * identification of flow statistic because DataStore/CONFIGURATION could contains
+ * a lot of flows with same flowCookie. So we are replacing original flowCookie
+ * with unique and we are building final FlowCookieMap in DataStore/OPERATIONAL
+ *
+ * @author <a href="mailto:vdemcak@cisco.com">Vaclav Demcak</a>
+ *
+ * Created: Jun 13, 2014
+ */
+public enum FlowCookieProducer {
+
+    INSTANCE;
+
+    /* Flow_Cookie_Key and Flow_Ids MapHolder */
+    private static final AtomicLongMap<InstanceIdentifier<Table>> cookieKeys = AtomicLongMap.create();
+
+    /**
+     * Method returns the unique cookie for a node table.
+     * Flow Cookie Key signs List<FlowId> for a right flow statistic identification
+     * in the DataStore/operational.
+     * We need a List<FlowId> because system doesn't guarantee unique mapping
+     * from flow_cookie to flow_id. REST Operations doesn't used FRM yet, so
+     * cookie from user input could have a user input flow ID and an alien system ID
+     * which is generated by system.
+     *
+     * @param InstanceIdentifier<Table> tableIdentifier
+     * @return unique BigInteger flowCookie for a node table
+     */
+    public BigInteger getNewCookie(final InstanceIdentifier<Table> tableIdentifier) {
+        FlowCookieProducer.validationTableIdentifier(tableIdentifier);
+        if ( cookieKeys.containsKey(tableIdentifier)) {
+            /* new identifier always starts from ONE because
+             * ZERO is reserved for the NO_COOKIES flows */
+            return BigInteger.valueOf(cookieKeys.addAndGet(tableIdentifier, 1L));
+        } else {
+            return BigInteger.valueOf(cookieKeys.incrementAndGet(tableIdentifier));
+        }
+    }
+
+    /**
+     * Method cleans the node table flow_cookie_key for the disconnected Node.
+     *
+     * @param InstanceIdentifier<Table> tableIdentifier
+     */
+    public void clean(final InstanceIdentifier<Table> tableIdentifier) {
+        FlowCookieProducer.validationTableIdentifier(tableIdentifier);
+        cookieKeys.remove(tableIdentifier);
+    }
+
+    /*
+     * Help the TableIdentifer input validation method
+     */
+    private static void validationTableIdentifier(final InstanceIdentifier<Table> tableIdent) {
+        Preconditions.checkArgument(tableIdent != null, "Input validation exception: TableIdentifier can not be null !");
+    }
+}